gpio: pca953x: fix gpio input on gpio offsets >= 8

This change fixes a regression introduced by commit
f5f0b7aa8 (gpio: pca953x: make the register access by GPIO bank)

When the pca953x driver was converted to using 8-bit reads/writes
the bitmask in pca953x_gpio_get_value wasn't adjusted with a
modulus BANK_SZ and consequently looks at the wrong bits in the
input register.

Signed-off-by: Andrew Ruder <andrew.ruder@elecsyscorp.com>
Reviewed-by: Gregory CLEMENT <gregory.clement@free-electrons.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

drivers/gpio/gpio-pca953x.c

@@ -308,7 +308,7 @@ static int pca953x_gpio_get_value(struct gpio_chip *gc, unsigned off)
 		return 0;
 	}
 
-	return (reg_val & (1u << off)) ? 1 : 0;
+	return (reg_val & (1u << (off % BANK_SZ))) ? 1 : 0;
 }
 
 static void pca953x_gpio_set_value(struct gpio_chip *gc, unsigned off, int val)